Coolant condenser

ABSTRACT

The invention relates to a coolant condenser comprising a network consisting of pipes and ribs, collecting tubes arranged on both sides of the network a parallelly arranged collector which is connected through the coolant to the collecting tube or condenser by means of overflow holes. A filter insert is located in the collector, which is connected to a closure plug, wherein said insert has a peripheral sealing arranged between the overflow holes.

The invention relates to a coolant condenser having a network composedof tubes and ribs, collecting tubes arranged on both sides of thenetwork and having a collector which is connected to one of thecollecting tubes by means of at least one inflow opening and at leastone outflow opening and is arranged in parallel with it, in particularaccording to the preamble of patent claim 1 or claim 10.

The invention also relates to an insert part for a collector of acondenser of an air-conditioning system for motor vehicles, inparticular according to the preamble of patent claim 13.

The condenser which is known from DE-A 197 12 714 by the applicant iswhat is referred to as a condenser module which is characterized by acollector which is integrated with the condenser. In this context, thiscollector is of tubular design, is arranged in parallel with one of thetwo collecting tubes of the condenser and is connected fluidically tothe adjacent collecting tube via an inflow opening and an outflowopening. A dryer/filter cartridge is positioned in the collector and isconnected in a positively locking and detachable fashion to a closurestopper by means of a latch connection. After the condenser has beensoldered, the dryer/filter cartridge is inserted into the collector,which is then sealed in a fluidic and pressure-tight fashion by theclosure stopper. The dryer/filter cartridge has a plastic housing with acircumferential sealing lip which is arranged between the inflow openingand the outflow opening and divides the collector into an inflow spaceand an outflow space. After the coolant flows through the dryer/filtercartridge, it thus passes out of the inflow space into the outflow spaceand thus back into the network of the condenser. A detailed descriptionof such a condenser module can be found in DE-A 44 02 927 by theapplicant. The flow through the dryer/filter cartridge which is filledwith granulate causes a considerable drop in pressure for the coolant,which, after it emerges from the condenser, flows through the entirecollector until it re-enters the supercooling section of the condenser.

Further designs of dryer/filter cartridges have been disclosed by DE 20004 438 U1, FR-A 2 750 761 and EP-A 0 921 022. In DE '438 spacer elementsare necessary to position the dryer/filter cartridge in the collector.In the dryer/filter cartridge according to EP '022 and FR '761 adividing wall is necessary in the collector and the lower end of thedryer/filter cartridge is inserted into said dividing wall while theupper end is connected to the closure stopper. A disadvantage with thesedesigns is that the cartridge is relatively long and not easy to handlein terms of installation and removal.

An object of the present invention is to improve a coolant condenser oran insert part of the type mentioned at the beginning in such a way thatthe number of individual parts for a dryer/filter unit and possiblytheir costs are reduced, and the installation and removal of the unitare also possibly facilitated.

The means of achieving this object are apparent from the features of theindependent claim 1.

The spatial separation of the drying and filtering of the coolant givesrise to a smaller drop in pressure for the coolant which flows throughthe collector. This reduced pressure loss has a positive effect on theperformance of the entire condenser. Furthermore, the drying/filteringfunction unit is simplified in terms of its design because additionalindividual parts such as spacer elements are dispensed with. Arrangingthe closure stopper and the insert which is connected to it in the lowerregion of the collector, that is to say in the region of the inflow andoutflow openings, makes the entire insert shorter.

According to one advantageous refinement of the invention, the insert isof pot-shaped design and embodied as a separate filter unit which iseither designed to be clipped to the closure stopper as a mounted unitor is embodied in one piece with it as an injection molded part. Thefiltering effect is functionally improved insofar as the coolant flowsfirstly into the interior of the pot-shaped insert, from there radiallyoutwards via filter sieves into an annular space and from there backinto the condenser. The arrangement of the filter sieves on thecircumference produces a larger filter passage area and thus a smallerdrop in pressure for the coolant. Particles of dirt which are held backby the sieve can collect on the bottom of the pot-shaped insert and thusdo not block the filter. The manufacturing costs can be reduced bymanufacturing the insert and closure stopper as a single-piece injectionmolded part, whether from plastic or from an aluminum alloy. As a resultof the closure stopper being secured in the collector, the insert issimultaneously positioned in the collector, which is significant inparticular for the sealing lip since it has to be arranged between theinflow opening and the outflow opening.

According to one advantageous development of the invention, the dryingis carried out by means of a small bag of desiccant which is positionedabove the filter insert, which is permeable to the coolant and holds adesiccant in granulate form in its interior. This little bag issupported on the edge of the pot-shaped insert so that the cavity in theinterior of the filter insert remains free.

Advantageous developments emerge from the features of claims 2 to 9.

A further solution is obtained according to the features of claim 10.Here, the filter insert as a single-piece plastic injected molded partis lengthened to form a dryer cartridge which holds the desiccant ingranulate form. It is thus possible to introduce the desiccant andfilter from below into the collector as one part with the closurestopper and position it there in its operating position. The upper partof the dryer cartridge, i.e. above the sealing lip, has a relativelylarge circumferential area which is penetrated by windows and is coveredby a relatively large-mesh filter fabric. As a result, relatively largeparticles of dust remain outside the cartridge. The lower part of thecartridge, i.e. below the sealing lip, also has window-likebreakthroughs which are however covered by a relatively fine-mesh filtersieve. The combination of large-mesh and fine-mesh filters reduces thedrop in pressure of the cartridge.

According to a further advantageous refinement of the invention, thedryer cartridge with the closure stopper which is manufactured in onepiece from plastic, forming the insert part, is sealed with respect tothe collector by means of O rings. As a result of the internal pressurein the collector, the closure stopper which is partially of hollowconstruction is widened somewhat owing to the lower modulus ofelasticity of plastic so that the O rings are additionally pressed andthe sealing effect is thus increased.

Advantageous developments emerge from the features of claims 11 and 12,and 14 to 23.

The invention is illustrated by way of example in the drawing withreference to exemplary embodiments and is described in more detailbelow.

FIG. 1 shows a filter insert, connected to a closure stopper by a clipconnection,

FIG. 2 shows a filter insert, manufactured in one piece with the closurestopper, in a collecting tube, and

FIG. 3 shows a dryer/filter cartridge which is manufactured in one pieceas a plastic injection molded part.

FIG. 1 has an insert 1, composed of a closure stopper 2 and a filterinsert 3. This insert 1 is inserted, similarly to the prior artdescribed at the beginning, into a collector (not illustrated here) of acoolant condenser for an air-conditioning system of a motor vehicle. Theclosure stopper 2 is embodied in a similar way to that described in DE-A100 39 260 by the applicant, i.e. it has, on its circumference, twoannular grooves 4 into which O rings (not illustrated) are inserted inorder to seal the closure stopper with respect to the inner wall of thecollector (not illustrated). The closure stopper 2 is manufactured froman aluminum alloy and is secured in the collector in both directions.The filter insert 3 is connected in a positively locking and detachablefashion to the closure stopper 2 by means of a clip connection orlatching connection 5 and is thus also centered with the closure stopper2. The filter insert 3 is of pot-shaped design, i.e. it has a bottom 6,a cylindrical wall 7 and an edge 8 which is continuous toward theoutside in the radial direction with an elastic circular sealing lip 9.The wall 7 is penetrated by rectangular windows which are distributedover the circumference, of which two windows 10, 11 can be seen in thesectional view in the drawing. In each case webs 12 are left betweenthese windows 10, 11. The window-like breakthroughs 10, 11 are coveredby fine-mesh filter fabric 14, 14. As a result, the pot-shaped insert 3has a cylindrical free interior 15 which is manufactured as a plasticinjection molded part.

FIG. 2 shows a further exemplary embodiment in which an insert 20 iscomposed, as a single-piece injection molded part, composed of a closurestopper part 20 a and a filter part 20 b. Moreover, both the closurepart 20 a and the filter part 20 b are of similar design to theexemplary embodiment according to FIG. 1, with the difference that theclip connection 5 is dispensed with for the sake of the single-piecedesign. The insert 20 is inserted into a partially illustrated collector21, sealed by O rings 22 and secured axially by means of a securing ring23 (as is also known from the abovementioned prior art). The collector21 of tubular design has an inflow opening 24 and an outflow opening 25via which the coolant of the condenser (not illustrated) flows into theconnector 21 and flows out of it again. Arranged between these twoopenings 24, 25 is a sealing lip 20 c which is formed on the insert 20in its upper region 20 b and which divides the interior of the collector21 into an inflow space 26 and an outflow space 27 which is formed as anannular space in the region of the outflow opening 25. A little bag 28of desiccant is loosely arranged above the insert 20, i.e. above thesealing lip 20 c; said little bag 28 is filled with a known desiccant ingranulate form and thus draws moisture out of the coolant. Window-likebreakthroughs 30, covered with a filter fabric 29, are arranged at thelevel of the annular space 27, as in the exemplary embodiment accordingto FIG. 1.

The function of the abovementioned dryer/filter unit is as follows: thecoolant, represented by an arrow E, enters the inflow space 26 of thecollector 21 where it comes into contact with the little bag 28 ofdesiccant or with the granulate located in the interior of the littlebag 28. The coolant flows through and around the bag 28 since the latterdoes not fill the entire free cross section of the collector 21. Thecoolant from which moisture has thus been removed then enters theinterior space 31 of the insert part 20 b. The coolant is present herein the liquid phase and leaves the interior space 31 radially throughthe filter fabric 29 toward the outside, enters the annular space 27 andflows from there via the outlet opening 25, following the arrow A, intothe condenser (not illustrated here) or its collecting tube (notillustrated either). From there, the coolant reaches a supercoolingsection of the condenser (not illustrated).

FIG. 3 shows a dryer/filter cartridge 33 in which a closure stopper 34,a filter insert 35 and a dryer sleeve 36 are embodied in one piece as aninjection molded part with a circumferential sealing lip 37. The closurestopper 34 and the filter insert 35 in conjunction with the sealing lip37 are embodied in a similar way to those in the previous exemplaryembodiments according to FIG. 1 and FIG. 2, i.e. inside the filterinsert 35 there is an approximately cylindrical cavity 38 which isconnected to the outside via filter openings 39. The dryer cartridgewhich is arranged above the sealing lip 37 as a prolongation of thefilter insert 35 is composed of a cage-like sleeve 40 which has aplurality of breakthroughs 41 which are also covered by a filter fabric42 (illustrated by cross hatching). The sleeve 40 in which granulate(not illustrated) for drying the coolant is located contains, in itsupper region, a pressure plate 43, a compression spring 44 and a closurecap 45 which is supported on the outside by a cross-sectionalconstriction 46 of the sleeve 40. The entire dryer/filter cartridge 33is positioned in the collector (not illustrated) by the closure stopper34, i.e. additional spacer elements are not necessary. The unit 33 ispushed into the collector tube from below, i.e. in the region of thecondenser where the outflow opening (cf. FIG. 2, reference number 25) islocated. This results in a minimum overall length for the entiredryer/filter unit 33.

The closure stopper 34 can be embodied in a similar way and be attachedin the collector as described in the abovementioned DE-A 100 39 260 bythe applicant. Here, owing to the construction using plastic which has alower modulus of elasticity than, for example, aluminum, an additionaladvantage is obtained: as a result of the internal pressure in thecollector which also acts on the interior of the closure stopper 34which is of partially hollow construction, said closure stopper 34widens toward the outside, i.e. in the radial direction, so that the Orings (not illustrated here) are pressed somewhat more strongly and thusbring about a better sealing effect.

Overall, there is a favorable drop in pressure for the dryer/filtercartridge 33 because a relatively large and large-mesh filter surface isavailable in the upper region of the cartridge, i.e. above the sealinglip 37, while a fine-mesh filter is provided in the lower region, i.e.below the sealing lip 37.

1. A coolant condenser having a network composed of tubes and ribs,collecting tubes arranged on both sides of the network and having acollector which is connected to one of the collecting tubes by means ofat least one inflow opening and at least one outflow opening and isarranged in parallel with it and in which an insert which is connectedto a closure stopper and has filter means is arranged, the insert havinga circumferential sealing means which is arranged between the inflowopening and the outflow opening, and the closure stopper being arrangedin the region of the outflow opening, characterized in that the filtermeans is embodied as a separate insert and as a functional unit and isarranged in the region of the outflow opening.
 2. The coolant condenseras claimed in claim 1, characterized in that the insert is of pot-shapeddesign and has a bottom, a wall and an edge, the wall having window-likebreakthroughs which are covered by filter sieves and the sealing meanswhich is embodied as a circumferential sealing lip being arranged at theedge (8).
 3. The coolant condenser as claimed in claim 1, characterizedin that the insert is connected to the closure stopper in a detachablefashion by means of a clip connection.
 4. The coolant condenser asclaimed in claim 1, characterized in that the insert is embodied in onepiece with the closure stopper.
 5. The coolant condenser as claimed inclaim 4, characterized in that the insert and the closure stopper aremanufactured as an injection molded part.
 6. The coolant condenser asclaimed in claim 5, characterized in that the injection molded part ismanufactured from plastic.
 7. The coolant condenser as claimed in claim5, characterized in that the injection molded part is manufactured froman aluminum alloy.
 8. The coolant condenser as claimed in claim 2,characterized in that the outer surface of the pot-shaped wall forms,with the inner wall of the collector in the region of the outflowopening, an annular chamber, and the inner surface of the pot-shapedwall and of the closure part form a free cavity.
 9. The coolantcondenser as claimed in claim 1, characterized in that desiccant in theform of small bags of granulate is positioned above the insert.
 10. Acoolant condenser having a network composed of tubes and ribs,collecting tubes arranged on both sides of the network and having acollector which is connected to one of the collecting tubes by means ofat least one inflow opening and at least one outflow opening and isarranged in parallel with it and in which an insert which is connectedto a closure stopper and has drying and filter means is arranged, theinsert having a circumferential sealing means which is arranged betweenthe inflow opening and the outflow opening, and the closure stopperbeing arranged in the region of the outflow opening, characterized inthat the insert is embodied as a single-piece component, such as inparticular an injection molded component, which is composed of theclosure stopper and a cage-like sleeve.
 11. The coolant condenser asclaimed in claim 10, characterized in that the sleeve has window-likebreakthroughs which are covered by filter sieves.
 12. The coolantcondenser as claimed in claim 10, characterized in that the closurestopper has circumferential annular grooves for receiving O rings. 13.An insert part for a collector of a condenser of an air-conditioningsystem for motor vehicles, composed of a closure stopper and a filterpart which is connected to the closure stopper and has a circumferentialsealing means, it being possible to insert the insert part from an endside of the collector, characterized in that the filter part is embodiedas a separate insert and functional unit.
 14. The insert part as claimedin claim 13, characterized in that the insert is of pot-shaped designand has a bottom, a wall and an edge, the wall having window-likebreakthroughs which are covered by filter sieves and the sealing meanswhich is embodied as a circumferential sealing lip being arranged at theedge.
 15. The insert part as claimed in claim 13, characterized in thatthe insert is connected to the closure stopper in a detachable fashionby means of a clip connection.
 16. The insert part as claimed in claim13, characterized in that the insert is embodied in one piece with theclosure stopper.
 17. The insert part as claimed in claim 16,characterized in that the insert and the closure stopper aremanufactured as an injection molded part.
 18. The insert part as claimedin claim 17, characterized in that the injection molded part ismanufactured from plastic.
 19. The insert part as claimed in claim 17,characterized in that the injection molded part is manufactured from analuminum alloy.
 20. An insert part for a collector of a condenser of anair-conditioning system for motor vehicles, composed of a closurestopper and having a dryer/filter cartridge which is connected to theclosure stopper, it being possible to insert the insert part from an endside of the collector, characterized in that the insert part is embodiedas a single-piece injection molded part which is composed of the closurestopper and a cage-like sleeve.
 21. The insert part as claimed in claim20, characterized in that the sleeve has window-like breakthroughs whichare covered by filter sieves.
 22. The insert part as claimed in claim20, characterized in that the closure stopper has circumferentialannular grooves for receiving O rings.
 23. The insert part as claimed inclaim 20, characterized in that the injection molded part ismanufactured from plastic.